Question

Let S be the universal set, where: S = {1, 2, 3, ..., 18, 19, 20} Let sets A and B be subsets of S, where: Set A = {2,5, 6, 7, 8, 14, 18} Set B = {1, 2, 3, 4, 7, 9, 10, 11, 12, 14, 18, 19, 20} Find the following: The cardinality of the set (A U B): n(AUB) = The cardinality of the set (A n B): n(An B) is You may want to draw a Venn Diagram to help answer this question.

Answer 1

Given that,

Set A = {2,5,6,7,8,14,18}

Set B = (1,2,3,4,7,9,10,11,12,14,18,19,20}

So, Set (A U B) included all the elements in either set A or Set B

So, Set (A U B) = {1,2,3,4,5,6,7,8,9,10,11,12,14,18,19,20}

or n(A U B) = 16

Similarly, Set (A⋂B) included all the element repeated in both the set.

So, Set(A⋂B) = {2,7,14,18}

or n(A⋂B) = 4